Comparison of Effects of Cobra Venom and Morphine on Unanesthetized Cat

Summary

1. In unanesthetized cats morphine induces progressive excitation of the central nervous system and neuromuscular apparatus while cobra venom effects a sedation proportionate to dose of neurotoxin given. 2. While even small doses of morphine produce extreme dilatation of the pupil, cobra venom in small doses has little or no effect on its size though in larger doses it causes a definite myosis. 3. The evidence presented proves that this narrowing of cat's iris is due to a central action of the drug, which heightens the tonus of the oculomotor nucleus.